ENGINE BLOCK COMPONENTS

There are many components of engine block. This part will discuss the seven major components and their related parts. These major components are camshaft pistons connecting rods crankshafts flywheel vibration damper  and oil pan. Let's begin with the camshaft.

1. The Camshaft

Camshaft are usually made from cast forged steel. The surface of the lobes are hardened for long life. In most cases the camshaft is located in the engine block and is supported and rotates, in series of bearings located along its length. It's purpose is to provide for the opening and closing of engine valves.

2. Pistons

When a flammable gas mixture ignited and burns, the gases expand producing heat and pressure. If the heat energy has nothing to work on, it will do nothing more than warm an area. The function of the piston is a hollow metal tube with the top enclosed. It is on this enclosed top that the heat energy works.The gunpowder would drive a cannonball through the barrel of the cannon when fired. If the energy produced by the burning gases is allowed to passed between the pistons and the cylinder walls, it is wasted energy;therefore, you must have a pressure-tight seal between the piston and the cylinder walls.Take a look at the piston as you can see near the top of the piston is series of land grooves.

The Piston

To obtain a pressure tight seal a series of rings is installed into the grooves near the top of the piston. Just below the lands and grooves is hole that extends through the piston. We will discuss the reason for the piston pin hole in more detail later. There are two types of rings compression rings and oil control rings. The top two rings are compression rings and are responsible for forming the pressure tight seal.

The piston moving in the cylinder causes friction. Even though the smooth surface of the cylinder walls helps to reduce the friction, the cylinder walls must be lubricated with oil but we cannot allow excess oil to remain on the cylinder walls. Oil remaining on the cylinder walls would be burned with gases when the piston travels down inside the cylinder. Eventually there would be no more oil to prevent or at excess oil from the cylinder walls as the piston travels downward.

Piston Rings

3.Connecting Rod

So far you have heat energy being converted to mechanical energy by pistons; but like heat energy , mechanical energy must have something to work on. If not, it is wasted. The piston traveling straight down must cause the wheels of the vehicle to rotate. That is the up and down motion (reciprocating motion) of the pistons must be connected to the crankshaft in a way that will allow for this change of motion occur. A component known as the connecting rod does this.

This is where the hole in the side piston is employed. A snug-fitted pin called piston pin is manufactured for this hole. The pin attaches the connecting rod to piston. This is done by inserting the pin through the holes in the side of the piston and through the piston pin bushing (a friction type bearing) located in a hole at the top of the connecting rod. The connecting rod is allowed to swing freely on the piston pin in much the same manner as your hand swing on your wrist. (For this reason, you will often hear the piston pin referred to as the wrist pin). The bottom of the connecting rod is connected to the crankshaft by bearing cap.

Connecting Rod and Related Parts

Okay so what was "reciprocating motion"? Yes, It's an up and down motion. And what delivers the power from the engine? Very good if you said the crankshaft.

4. Crankshaft

As stated previously, the crankshaft delivers power from the engine. The function of the crankshaft when aided by the connecting rod is the change the reciprocating motion of the pistons to rotary motion.The crankshaft extends through the length of the engine and has a series of throws and journal. Some of these journals are on the shaft itself, and others are located on the throws are connecting rod journals to be offset from the centreline of the crankshaft. The main journal cap is bolted over each of the crankshaft's main journals after the crankshaft is positioned in the crankcase.

Crankshaft Construction

The connecting rod journals provide a place to attach the connecting rod to the crankshaft. After the connecting rod is seated on the crankshaft, a connecting rod bearing cap is bolted over the journal to the connecting rod. Therefore when the piston is driven down in the cylinder, it drives the connecting rod, which drives the crankshaft to rotate.

The Crankshaft Changes Reciprocating Motion to Rotary Motion

5. Flywheel

In some engines there is brief interval when the pistons do not drive the crankshaft. However, with enough momentum, the crankshaft can travel through this brief portion of its rotation. To accomplish this, a large wheel known as the flywheel is bolted to the rear end of the crankshaft.

6. Vibration Damper

Under certain engine speeds and loads, the crankshaft tends to vibrate. To reduce this vibration, a small wheel known as the vibration damper is bolted to the front end of the crankshaft. Vibration dampers often serve as pulley for the fan, generator and accessory belts or they may have a pulley attached to accommodate the various belts.

Vibration Damper Location

With the exception of the flywheel and the vibration damper, all the moving parts discussed up to this point require lubrication (engine oil) stored inside the engine oil pan. So let's discuss the oil pan.

7. Oil Pan

The oil pan is the reservoir of the engine oil. It is a large metal pan fitted and bolted to the bottom of the crankcase. It enclose the crankcase and all moving parts. Oil picked up from the oil pan by the oil pump and distributed throughout the engine.

Oil Pan and related Parts.

COMPONENTS OF ENGINE

ENGINE BLOCK

Learning Objective:

Given a description of engine block functions, identify the engine block part described

The engine block is the main part of the engine; all parts of the engine are either inside the engine block or attached to the outside of it. The engine block is one-piece casting of iron, but actually it is considered in two parts, the crankcase and the cylinder block.

1. Crankcase

To illustrate the two parts of the engine block, an imaginary box has been drawn around the lower portion of the engine block. This lower portion is known as the crankcase. 

Four-cylinder engine block (left rear view)

The crankcase which support the crankshaft, is hallow inside with one or more rib-like castings that form the mainframe.

Eight Cylinder Engine Block

2. Cylinder Block The upper portion of the engine block is the cylinder block. This portion contains the cylinders, the water passages commonly known as water jacket and oil passages.

Engine Block Coolant Flow

Oil Passages

The cylinders are the individual housing for the pistons. They are large holes cast into the cylinder block, extending completely through it. The walls of the cylinders are machined smooth to reduce the friction generated by the moving parts inside them. Some engines have cylinder liners inserted into the cylinder opening.

The water jacket, a large passage cast into cylinder block, surrounds the cylinder. It contains water or commercial coolant to maintain safe temperature while the engine is operating.

Note the oil passage provide a way to distribute oil under pressure to all moving parts of the engine to reduce wear and aid the water jacket in cooling the moving parts.

Cylinder block (top view of cylinders and water passages). 

AUTOMOTIVE SYSTEM ENGINEERING

Systems Engineering has long been established in the fields of avionics and software development. In the automotive sector too, we are witnessing an increasing number of systems engineering approaches. Nonetheless, a distinct profile has still to be developed that clearly defines its limits and interfaces with other development and research areas and gives a specific identity to automotive systems engineering. Consequently, conferences and publications offering opportunities to exchange experience on this topic are also lacking. Despite the fact that many scientists and practitioners are working on Automotive Systems Engineering issues, a pinpointed community has not yet emerged that covers at least the major areas involved. Automotive Systems Engineering pools many disciplines, from control engineering, test development, development of mechanical engineering, electrical and electronic hardware and software. And through ergonomics, issues of human physiology and psychology also permeate through the driver-vehicle system.

Automotive Systems Engineering combines a multiple of disciplines, but being ‘‘sandwiched’’ between so many different stools its position is also weakened. Personal talks between the editors on this situation lead to a workshop where ASE- related activities were presented and an intensive exchange of experience was ini- tiated. The successful outcome resulted in this publication with the ambition of encouraging an exchange of experience beyond our two institutes. The topics covered in each chapter have their roots in doctoral theses still ongoing or nearing completion. They present the state of science centering on development method- ology and with a limited application focus. A clear heterogeneity is visible both within and between the institutes, although it would be feasible and also desirable to reach more harmonised approaches. The perspective pursued with this publication, therefore, is to enhance standardisation, both in the terminology used and in pre- valent definitions for methods—a common process when building communities. By means of workshops and specialised publications, we intend to advance the com- munity-building process together with a wider range of partners from academia and industry and trust that the present work will provide an appropriate foundation.

Alongside chapters presenting scientific studies, the editors’ subjective per- spectives on the topic are added, leaning on talks and lectures and their back- ground experience in academia and industry.

We wish our readers stimulating reading and look forward to receiving a wide spectrum of feedback to help us tread the path towards an automotive systems engineering community.

Markus Maurer Hermann Winner